Add se_compat_cil module

Installs backwards compatibility cil files.

Bug: 183362912
Test: Presubmit
Test: Add a $(ver).compat.cil under SYSTEM_EXT_PRIVATE_SEPOLICY_DIR and
  verify the file is installed under /system_ext/etc/selinux/mapping/
Change-Id: I5e2c6b8dfa8df431edfe96f29daae463b130367f
2 files changed